-char **strv_merge(char **a, char **b);
-char **strv_merge_concat(char **a, char **b, const char *suffix);
-char **strv_append(char **l, const char *s);
+int strv_extend_strv(char ***a, char **b);
+int strv_extend_strv_concat(char ***a, char **b, const char *suffix);